Technical Field
The embodiments described herein relate to geographical information systems.
Background Art
Geographic Information Systems (GIS) capture, store, manage and display data elements according to geospatial coordinates. For example, Google Earth renders satellite imagery, terrain, vectors and other data over a three-dimensional geometry representing the Earth's surface. Google Earth users can “fly” or navigate around a virtual Earth, while data and images corresponding to geographical locations are presented in varying degrees of detail.
In order to provide this user experience, an enormous amount of geospatial data may be organized and indexed into a “globe.” A globe is a directory hierarchy containing a number of bundled files that are organized in a way such that imagery, terrain, and vectors can be easily served to a client. High resolution globes are created by organizing tens of terabytes of imagery, terrain, and vector data that are fused together to create a navigable globe. The fused globe allows smooth panning and zooming to any view point, allowing in-context viewing of large amounts of data. The globes support both exploration as well as search for particular features.
These globes are invaluable tools for industry and government analysts and operational users who depend on access to the central servers that provide the globes' data to their “spinning earth” clients. However, sometimes such access is not available. For example, military, first responder, or relief efforts on the ground need access to globe data relevant to their area of interest, but there may be no way for them to connect to the large, central globe, or they may only have limited connectivity for short periods of time.